試題詳解

2. Since 2019, the magnitudes of all SI units have been defined by declaring exact numerical values for defining constants when expressed in terms of their SI units. Which one of the following constants is not included?
(A) the speed of light in vacuum, c
(B) the Planck constant, h
(C) the Coulomb constant, ke (or 1/4πε₀ )
(D) the Boltzmann constant, k (or kB)
(E) the Avogadro constant, NA